Thermochemical properties of Bi2CuO4

The heat capacity and the heat content of Bi2CuO4 were measured by Calvet calorimetry (300–570 K) and by drop calorimetry (670–970 K), respectively. The temperature dependence of the heat capacity in the form Cpm=185.249+1.453×10−3T−4.730×106T−2+4.620×108T−3 was derived by the least square method. The enthalpy of solution of Bi2CuO4 as well as the stoichiometric mixture of Bi2O3 and CuO in the lead borate melt were measured at 970 K. The heat of formation of Bi2CuO4 from the constituent binary oxides and elements at 298.15 K are −14.63±1.47 and −740.12 kJ mol−1, respectively.